USGS Coastal and Marine Geology Program

Coastal & Marine Geology Program

Field Activity Details for field activity 1975-009-FA

Other ID: ATL2 89-4; 89, Leg 4

Status: Completed

Organization(s): USGS, Woods Hole Coastal and Marine Science Center

Funding Program(s):

Location: Baltimore Canyon Trough area, outer continental shelf, United States, North America, North Atlantic;

Principal Investigator(s): Harley J. Knebel

Affiliate Investigator(s):

Information Specialist(s): Nancy K. Soderberg

Data Type(s): Location-Elevation: Navigation, Sampling: Biology, Sampling: Geology, Seismics: Sparker, Seismics: Sub Bottom Profiler

Scientific Purpose/Goals: This 4th leg of the ATLANTIS II cruise had 3 primary objectives. The first objective was to obtain long vibracores to deduce characteristics and ages of sub-bottom sediments. These cores were in support of the acoustic survey completed in Baltimore Canyon Trough in May 1974. Second, short cores of sub-bottom sediments were to be collected. By measuring relative amounts of Pb-210 in these short cores, ages and accumulation rates of sediments for the past 100 years could be determined. Finally, stability of sediments at shelf edge was to be studied. Near-surface (apparently recent) fault displacement had been observed in high-resolution seismic records, suggesting that a mechanism existed for generation of slumps at the shelf break and on the upper continental slope. In addition, several special studies were pursued: sampling surface sediments to determine trace metal and hydrocarbon contents; sampling suspended sediments at water surface; emplacement of pipes into the sea floor by vibracore rig to use as reference points during submersible dives; outlining the areal extent of a sand-wave field near Wilmington Submarine Canyon; dropping sea-bed drifters at selected sites; and outlining the path of the ancestral Delaware valley across the continental shelf.

Vehicle(s):

Start Date: 1975-06-01

Start Port/Location: Woods Hole, MA

End Date: 1975-06-12

End Port/Location: Woods Hole, MA

Equipment Used: 3.5 kHz, Alpine Vibracorer, Raytheon 3.5 kHz sonar (CESP II) system, Del Norte 26 sparker, Corer - piston, Smith-MacIntyre grab, Corer - gravity, Sediment traps, Magnavox satellite positioning system, Loran-C, Seismic Engineering streamer

Information to be Derived:

Summary of Activity and Data Gathered: Cruise concentrated on vibracoring and bottom sampling off New Jersey. 3.5 kHz records: 1774 km; Minisparker records: 659 km; Sample stations: 42; Bottom sediment samples: 78 (Vibracores: 19; Hydrostatically damped gravity cores: 37; Smith-McIntyre grab samples: 15; Gravity cores: 7); Suspended sediment samples: 50; Sea-bed drifters released: 57; Reference pipes emplaced in sea floor: 3.

Staff: Michael Bothner, Patricia Forrestel, Raymond E. Hall, William Jaworski, Frank W. Jennings, Harley J. Knebel, Francis A. Kohout, Charles Meeder, David Twichell

Affiliate Staff:
Bobb Carson - watch chief (Lehigh U./USGS); USGS-WRD: Grant Kimmel (Mineola
NY)
David Mazzaferro (Hartford
CT); US Coast Guard Academy: Douglas Fluddy
Edward Lane; Lehigh Univ.: David Huff; Alpine Geophysical Associates
Inc.: Charles Dill - Supervisor
Charles Gove
Bernard Katz

Notes: The 3.5 kHz system did not work properly during the bulk of the cruise; only a bottom trace could be obtained on the continental shelf and the signal usually was lost on the continental slope. It functioned as a fathometer during most of the cruise. The vibracore operations were hampered for several days by weather and sea state. Also (sometimes unpredictably), ship drift while anchored caused delays in time at station and retrieval of vibracore air hose. (The air hose fouled 3 times around the ship's rudder.) Thirdly, water-depth limitation caused the air hoses on the rig to collapse several times; maximum water depth for successful coring was 80 m. Also anchor deployment and weighing took more time than anticipated. Anchoring delays cut into total vibracoring time. Original Center People field also contained: Bob Carson - watch chief (Lehigh U./USGS).
Project = Geophysics of the Atlantic Outer Continental Shelf, Geophysics of the Atlantic Outer Continental Shelf

Location Map:

Platform(s):

photo of Atlantis II
Atlantis II

Publications

Chaytor, J.D., ten Brink, Uri S., Solow, Andrew R., and Andrews, Brian D., 2009, Size distribution of submarine landslides along the U.S. Atlantic margin: Marine Geology, v. 264 no. 1-2, doi: 10.1016/j.margeo.2008.08.007.

Geist, E.L., Lynett, Patrick J., and Chaytor, Jason D., 2009, Hydrodynamic modeling of tsunamis from the Currituck landslide: Marine Geology, v. 264 no. 1-2, doi: 10.1016/j.margeo.2008.09.005.

ten Brink, U.S., Barkan, R., Andrews, B.D., and Chaytor, J.D., 2009, Size distributions and failure initiation of submarine and subaerial landslides: Earth and Planetary Science Letters, v. 287 no. 1-2, doi: 10.1016/j.epsl.2009.07.031.

Twichell, D.C., Chaytor, Jason D., ten Brink, Uri S., and Buczkowski, Brian, 2009, Morphology of late Quaternary submarine landslides along the U.S. Atlantic continental margin: Marine Geology, v. 264 no. 1-2, doi: 10.1016/j.margeo.2009.01.009.

Data Acquired

Survey EquipmentSurvey InfoData Type(s)Data Collected
3.5 kHz --- Sub Bottom Profiler
1975-009-FA-BA-001 ( Digital tape(s) of NV-2 TRKCHTS, BT, )
Alpine Vibracorer --- Geology
Raytheon 3.5 kHz sonar (CESP II) system --- Sub Bottom Profiler
Del Norte 26 sparker --- Sparker
Corer - piston --- Geology
Smith-MacIntyre grab --- Biology
Geology
Corer - gravity --- Geology
Sediment traps --- Geology
Magnavox satellite positioning system --- Navigation
Loran-C --- Navigation
1975-009-FA-LN-001-03 ( Track Map - Southern Area (pdf file) Southern portion of computer plotted track map.)
1975-009-FA-LN-001-02 ( Track Map - Northern Area (pdf file) Northern portion of computer plotted track map.)
1975-009-FA-LN-001-01 ( Track Map (pdf file) Generalized drafted track map.)
1975-009-FA-LN-002-01 ( Zip archive of Navigation data)
Seismic Engineering streamer --- Air Gun / Water Gun
Boomer
Sparker
1975-009-FA-SE-001 ( Collection of paper record displays of seismic data( MSP) for lines )
1975-009-FA-SE-002 ( microfilm of )
1975-009-FA-SE-003 ( analog tape of seismic data)